title: Decomposition of Ag-based soldering alloys used in space maintainers after intra-oral exposure. A retrieval analysis study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the elemental alterations of Ag soldering alloys used in space maintainers after intra-oral exposure.
  
  
  METHODS
  Twenty devices were fabricated by using two different soldering alloys; US (Dentaurum Universal Silver Solder, n = 10) and OS (Leone Orthodontic Solder, n = 10). All devices were manufactured by the same technician. Surface morphology and elemental quantitative analysis of the soldering alloys before and after intra-oral placement in patients was determined by scanning electron microscopy and energy-dispersive X-ray microanalysis (SEM/EDX). Statistical analysis was performed by t-test, Mann Whitney tests and Pearson's correlation. For all tests a 95% confidence level was used (α = 0.05).
  
  
  RESULTS
  Both soldering alloys demonstrated substantially increase in surface roughness after intra-oral aging. Statistical analysis illustrated a significant decrease in the Cu and Zn content after treatment. OS demonstrated higher Cu release than US (p < 0.05). The remaining relative concentrations of Cu and Zn after the treatment did not show any correlation (p > 0.05) with intra-oral exposure time, apart from Zn in OS (r = 0.840, p = 0.04).
  
  
  CONCLUSIONS
  Both soldering alloys demonstrated a significant Cu and Zn reduction after intra-oral exposure that may raise biocompatibility concerns.
authors.affiliation: Department of Pediatric Dentistry.
authors.forename: Despo
authors.initials: D
authors.lastname: Soteriou
authors.forename: Argyro
authors.initials: A
authors.lastname: Ntasi
authors.forename: Lisa
authors.initials: L
authors.lastname: Papagiannoulis
authors.forename: Theodore
authors.initials: T
authors.lastname: Eliades
authors.forename: Spiros
authors.initials: S
authors.lastname: Zinelis
mesh_terms: D000497:Alloys; D009967:Orthodontic Appliances; D012834:Silver / Q000737:chemistry*
chemical_list: D000497:Alloys; D012834:Silver